Citing US government sources, NBC reported that Israel financed, trained and armed the MEK to carry out the deadly attacks on Iranian nuclear scientists. That Israel had a role in the assassination of the scientists took few by surprise. That it collaborated with a fundamentally anti-Israeli, Marxist-Islamist terror organization to pull off the attacks was perhaps a bit more surprising. (That the Obama administration would divulge this information and embarrass its close ally Israel publicly was also unexpected.)

The MEK’s history of violence and anti-Israeli activities is long and bloody. In the 1970s, it established deep ties with Yasser Arafat and both provided and received training from the PLO fighters. Much of the late Shah’s antipathy towards Arafat was rooted in the latters ties to the MEK and other opponents of the Pahlavi dynasty, publicly complaining “that some of the groups of the [Palestinian] resistance trained Iranian saboteurs to infiltrate our territory, kill our people and blow up various installations.”

Only days after the 1979 revolution toppled the Shah’s regime, Arafat showed up uninvited in Tehran, hoping that his investment in the Iranian opposition would translate into political, financial and military support to the PLO by the new Iranian regime.

Massud Rajavi, the head of the MEK, greeted Arafat in Tehran with a Kalashnikov as a welcoming gift. When Saddam Hussein invaded Iran in 1980, Rajavi fled Iran for Iraq, where he enjoyed the protection of Saddam Hussein until 2003. A former MEK fighter told me that Arafat visited the MEK’s military camp in Iraq (Ashraf).

Israeli diplomats knew that whoever seized power in Iran in 1979 would be no lover of Israel—whether it was the Islamists who opposed Israel on religious and ideological grounds, or the leftists who viewed Israel as an outpost for American imperialism in the region. The MEK was unique since it fell in both categories.

Exactly when Israel’s ties with the MEK were established is unclear. But by the early 1990s, as I describe in my book, a relationship was forming, though its full nature and extent remains unknown.

At the time, Deputy Defense Minister Ephraim Sneh pushed Yitzhak Rabin to signal Tehran that Israel could also play the terrorist card. Sneh argued that whenever Iran used Islamic Jihad or Hamas to blow up a bus in Jerusalem, Israel should use the MEK to respond in kind in Tehran.

But cooler heads prevailed. Rabin refrained from entering into a public relationship with the organization. But the Labor government left the door to the MEK half open: it permitted the Iranian terrorist group to use two Israeli satellites to beam their TV broadcasts into Iran.

Even the MEK’s alleged revelation of the Iranian nuclear facilities at Natanz in 2002 was based on information leaked to the organization by Israel, according to Israeli intelligence expert Ronen Bergman. Indeed, a former US State Department official told me recently that while Israel does not publicly acknowledge its ties to the MEK, Israeli officials privately tell the US that the MEK is “useful.”

All of this has fueled suspicions in DC that the current multi-million dollar lobbying campaign by the MEK to get off of the State Department’s terror list is bankrolled by Israeli sources. Dozens of former US officials have received tens and thousands of dollars in speakers’ fees from the MEK or its surrogates to speak out on their behalf. These former officials have likely violated US laws on material support to terrorist organizations, and several of them have had their records subpoenaed by the US Treasury in an ongoing investigation.

Political one-night stands are not unusual in the Middle East. Even tactical collaboration with sworn enemies takes place. But associating Israel with a cultish Iranian terror group is damaging to Israel on several levels.

First, any attempt by Israel to hold the higher moral ground and point fingers at the regime in Tehran will be lost if Israel itself is entangled with violent terrorist groups that kill indiscriminatingly. This may have implications for other states’ willingness to collaborate against terrorist groups targeting Israel.

Second, if Israel teams up with an organization described by the US State Department as “fundamentally undemocratic” and “not a viable alternative to the current government of Iran,” the argument that peace in the region would be achieved if only the other states in the region were as democratic as Israel will become even more unconvincing.

And finally, this will likely undermine Israel’s ability to rebuild ties with the Iranian people down the road. The MEK has the dubious honor of being the only entity more disliked by the Iranian people than the Iranian regime itself.